Kent James January 24, 2012 Announcements

ExQuilla is an addon for Mozilla's Thunderbird email client that allows access to both messages and contacts stored on Exchange Server 2007 - 2015. ExQuilla uses EWS (Exchange Web Services) for access to the server. ExQuilla (for versions beginning with 45.*) will work with either Thunderbird 38.* or 45.* on Windows, Linux, and OSX platforms. (Earlier ExQuilla versions worked with earlier versions of Thunderbird, but are no longer being updated.)

ExQuilla is not free software, but is licensed on an annual basis. New users are granted a free 60 day trial license automatically. For further information on ExQuilla licensing, see the ExQuilla Licensing Overview page.


You may download the current revision of ExQuilla from this link:

Windows:  http://mesquilla.net/exquilla-currentrelease-tb-windows.xpi

Linux: http://mesquilla.net/exquilla-currentrelease-tb-linux.xpi

OSX: http://mesquilla.net/exquilla-currentrelease-tb-osx.xpi


To install, download and save this file. Then from Thunderbird, open Tools/Add-ons, click on the Addon tools button  AddonActionsIcon.png and select "Install Add-on From File". Install the downloaded file, then restart Thunderbird.


The current version of ExQuilla supports messages and contacts. Calendar features are not supported.

Supported Messaging Features

  • Normal reading, replying, composing, sending email
  • attachments
  • Thunderbird message filters
  • Thunderbird's bayesian junk mail filters
  • Virtual folders and folder-level search

Unsupported Messaging Features

  • Synchronizing Thunderbird tags and Exchange categories
  • Offline message sending
  • Thunderbird message starring is not synchronized with Exchange message flags
  • S/MIME messages can be read but not sent

Supported Contact (Address Book) features

  • Most standard Thunderbird fields
  • Subfolders of Exchange "Contacts" folder

Unsupported Contact (Address Book) features

  • Exchange-only fields (such as Spouse)
  • User photo

Instructions and Support

After installation, follow these instructions to add an Exchange Server account to Thunderbird. For additional information or help, see ExQuilla's help resources, as a question on the general forum, or submit a support ticket (login required).

License Purchase

To buy an individual license, go to this webpage:


To buy a domain license, go to this webpage:


Individual licenses cost $10 per year.

Domain licenses cost  $25 per domain plus $5 per user (with a minimum of 5 users), per year.


Kent James April 15, 2015 Announcements

We have released an updated version of ExQuilla, version 38.0.1156, that supports both Thunderbird 31 as well as Thunderbird 38.

Existing users who downloaded ExQuilla from the mesquilla.net site should be updated automatically within a few days. Users who downloaded from the Mozilla addons site will need to wait a few weeks until the review is complete there, or you may download the current revision of ExQuilla from these links:

Windows: http://mesquilla.net/exquilla-currentrelease-tb-windows.xpi

Linux: http://mesquilla.net/exquilla-currentrelease-tb-linux.xpi

OSX (Mac): http://mesquilla.net/exquilla-currentrelease-tb-osx.xpi

Major changes in the version since the previous version (31.0.1136):

  • Support for Thunderbird 38 added, support for Thunderbird 24 dropped (but see note below)
  • Fixed: Startup failure fixed for profiles with large numbers of folders
  • Multiple connections to the Exchange server are supported, speeding up message sync
  • If a custom form-based authentication is used, the custom form will now popup to allow entering account credentials.
  • Autodiscover will be used to update the URL if connection to the server fails
  • Fixed: SaveAll encoded the attachment name incorrectly
  • Hidden folders are now hidden in the folder tree
  • Support Thunderbird's fcc reply follow parent option

If for some reason you are still running the older Thunderbird 24 release (24.2 or later), you will not be automatically downloaded. However, you can download the updated ExQuilla, released as version 31.1.1156, that will work with Thunderbird 24 or 31:

Versions compatible with Thunderbird 24 (and 31):

Linux: http://mesquilla.net/releases/exquilla-mn-esr31-31.1.1156-linux.xpi

Windows: http://mesquilla.net/releases/exquilla-mn-esr31-31.1.1156-windows.xpi

OSX: http://mesquilla.net/releases/exquilla-mn-esr31-31.1.1156-osx.xpi